Variable field microscope



Apnl 8, 1947. o. w. RICHARDS VARIABLE FIELDMICROSCOPE Filed NOV. 13,1943 2 Sheets-Sheet 1 INV ENT OR.

April 8, 1947- o. w. RICHARDS 2,418,601

VARIABLE FIELD MICROSCOPE Filed Nov. 15, 1943 2 sheets-sheet 2 oscAe vye/cH/leps A; TORNEY ings.

Patented Apr. 8, 1947 VARIABLE FIELD MICROSCOPE Oscar W. Richards,Snyder, N. Y., assignor, by

mesne assignments, to American Optical Company, Southbridge, Mass., avoluntary association Application November 13, 1943, Serial No. 510,090

3 Claims. (01. 88-39) This invention relates to new and usefulimprovements in microscopes or the like and has particular reference forsimply and quickly chan ing the contrast between portions of the fieldviewed through the microscope.

An object of the invention is to provide new and improved means wherebythe contrast between portions of the field of view through a microscopemay be easily and quickly changed to allow the viewing of the fieldunder such different contrast.

Another object of the invention is to provide new and improved means forinterchangeably supporting a plurality of light altering members inconjunction with a microscope whereby a desired member may be rapidlyaligned with the optical system of the microscope.

' Another I object of the invention is to provide a carrier forsupporting a plurality of series of light altering members relative to amicroscope whereby any desired member of either series may be easily andquickly aligned with the optical system of the microscope.

Other objects and advantages of the invention will be apparent from thefollowing description taken in connection with the accompanying draw- Itwill be understood that many changes may be made in the details ofconstruction'and arrangement of parts without departing from the spiritof the invention as expressed in the accompanying claims. I, therefore,do not wish to be Fig. 5 is a sectional view taken on line 5-5 of Fig.4;

.Fig. 6 is a sectional view. taken on line 65 of Fig.4; and

Fig. 7 is a view similar to Fig. 4 but showing a modified form of theinvention.

In the application of Osterberg et al., Serial Number 456,726, filedAugust 28, 1942, is disclosed an arrangement for viewing objects throughthe microscope under what is called a phase contrast technique. Thismethod as disclosed in said Osterberg application involves the use of aseries of discs, each having different light altering properties withmeans for quickly and easily interposing any desired member of theseries in proper position in the path of light through the microscopewhereby the contrast between different parts of the field is altered,the type of change depending upon the particular characteristics of thespecimen under view and the disc of the series interposed in the lightpath.

The series may contain numerous discs each having different lightaltering characteristics or the series may be composed of two differentkinds of discs, such as for example, one set which allows the specimento be seen as light on a dark background and the other set which allowsthe specimen to be seen dark on a light background. Each of these typesof discs have certain advantages for the observation of diiferentspecimens or different parts of a single specimen and in this case it isdesirable that means be provided whereby each disc of a set may berapidly interposed in the light path of a microscope and then the bestdisc of each series or set be easily and rapidly interchanged to allowobservation of the specimen or parts thereof, successively at will. Itis, therefore, an object of the present invention to provide meanswhereby each disc of a set may be rapidly aligned with the optical pathof a microscope and whereby a desired disc from each series or set maybe rapidl and easily interposed, alternately, in the light path of theviewing instrument.

Referring more particularly to the drawings wherein similar referencecharacters designate corresponding parts throughout the several views,the microscope shown in conjunction with the invention in Fig. 1comprises a base I supporting the upright arm 2 which carries themicroscope body tube 3. This body tube 3 supports the eyepiece 4,nosepiece 5 and objective 6.

On the base I is positioned the stage I having the opening 8therethrough whereby light from the mirror or reflector 9 may passthrough the condenser arrangement Ill and specimen or slide H to theobjective 6 and thus to the eyepiece 4 through which eyepiece thespecimen on slide H may be observed.

The condenser arrangement I!) as described in the Osterberg et al.application mentioned above contains the usual condensing lenses i2 andalso contains the circular aperture or diaphragm I3 as shown in Fig. 3.This condenser arrangement is adapted to co-operatively function withthe disc which is in the light path of the microscope to increase thecontrast between the specimen and the background or between difierentportions of the specimen as set forth above.

In the arrangement shown there are two rotatable mounts I l and i 5 eachcontaining a series of discs 56 and I? respectively. These rotatablemounts I4 and iii are mounted on a pivotal carrier l8 which is pivotallycarried by the arm Isa which is connected to the support for the bodytube of the microscope. Adjacent the center of the carrier I8 is anintermediate opening or aperture l9 adapted to be aligned with theoptical path of the microscope when it is not desired to employ eitherof the series of discs 16 or ll.

Surrounding the mounts l4 and I5 and carrier I8 is the cover 20 whichexcludes light and dust etc. from the discs and also from the interiorof the objective 6 which is threadedl connected at 2| to the lower endof the tubular member 22 which is threadedly secured to the nosepiece at23 and which allows the interchanging of objectives without interferingwith the discs 14 and [5.

The discs [4 and I5 are rotatably mounted at 24 and 25 to two oppositelyextending arms of the carrier l8.

In the form of the invention shown in Fig. 7 the carrier 26 extendsthrough slots in the carrier 22 and the support 26 has the intermediateopening 27 for alignment with the optical path of the instrument in amanner similar to the opening iii in the carrier l8. In this form therotatable mounts l4 and l 5 are pivotally secured to the carrier 26 at-24 and 25 respectively as previously described.

It will be seen that by employing the construction of this applicationthat it is possible for the observer to use the microscope withoutemploying either series of discs and also that by merely pivoting thecarrier l8 or sliding the carrier 26 he can align a particular serieswith the optical path of the instrument and then by rotating therotatable mount can successively observe the image through each of thediscs of that series until the desired contrast is obtained and then bypivoting or sliding the other series of discs into alignment with theoptical path he'can ascertain the disc of that particular series whichgives the desired or best contrast and then these best discs 28 and 29may be easil and quickly interchanged in the light path of theinstrument by either pivoting the carrier 18 on the pivot [90! orsliding the carrier 26 in the form shown in Fig. 7 so that the specimenmay be viewed alternately through each of said best discs of theirrespective series quickly and without loss of time and withoutinterferring with the optical set up of the instrument nor disturbin thespecimen.

The handle [8a on the carrier 18 allows the pivoting of said carrier 58and the mounts I4 and I5 into and out of operative position and the cutout portions 26a in the cover 29 allows the rotating of the mount id orl5 which is in use.

In the form shown in Fig. 7 the handle 2611 allows the shifting of themounts I4and l5 and the cut out portions 26a allow the rotation of thesaid mounts to align the desired light altering member with the lightpath of the microscope.

From the foregoing it will be seen that I have provided simple,efiicient and economical means for obtaining all of the objects andadvantages of the invention. 8

Having described my invention, I claim:

1. In a microscope having a condenser with a predetermined aperturecontrolling the cross section of the beam of light illuminating theobject to be observed and an objective for forming an image of saidobject, means for modifying the image thus formed so as to be seenselectively as light on a dark background or dark on a light backgroundcomprising a movable carrier, and a pair of mounts each swivelled onsaid carrier, one of said mounts being provided with a series of opticalmembers for producing various amounts of contrast in said image with theobject seen as .4 light on a dark background, the other of said mountsbeing provided with a different series of optical members for producingvarious amounts of contrast in said image with the object seen as darkon a light background, movement of said carrier in one directionbringing one of said mounts into operative relation to said condenserand objective and movement thereof in the opposite direction bringingthe other of said mounts into operative relation to said condenser andobjective, each mount being adjustable by swivelling on said carrier tobring a selected optical member into alignment with the optic axis ofsaid objective.

2. In a microscope, the combination with a. microscope objective, aslotted tubular support for the microscope objective and a condenserwith a predetermined aperture controlling the cross section of the beamof light illuminating the object to be observed, of means for modifyingthe image formed by said objective comprising a carrier movable relativeto said slot, and a pair of mounts each swivelled on said carrier, oneof said mounts being provided with a series of optical members forproducing various amounts of contrast in said image with the objectseenas light on a dark background, and the other of said mounts beingprovided with a different series of optical members for producingvarious amounts of contrast in said image with the object seen as darkon a light background, one of said mounts being inserted in said slottedtubular support when said carrier is moved relative thereto in onedirection and the other mount being substituted therefor in said slottedsupport when said carrier is moved in the other direction, ea'ch mountbeing adjustable by swivelling to bring a selected optical member intoalignment with the optic axis of the microscope objective.

3. In a microscope, the combination according to claim 2 together with acover for housing said mounts and protecting said optical members andslotted support from dust, said cover being provided with fingeropenings in operative relation to said mounts to permit adjustment ofsaid mounts to bring a selected optical member into alignment with theoptic axis of the microscope objective.

OSCAR W. RICHARDS.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 2,009,145 Nathan July 23, 19351,385,696 Marshall July 26, 1921 2,078,181 Land Apr. 20, 1937 182,919Gundlach Oct. 3, 1876 1,544,973 Ghadiali July 7, 192-5 2,152,513 WestMar. 28, 1939 2,151,735 Bresser Mar. 28, 1939 1,626,841 Kelley May 3,1927 561,132 Roche June 2, 1896 2,105,671 Roesch Jan. 18, 1938 2,205,179Schultz June 18, 1940 513,912 Gardam Jan. 30, 1894 FOREIGN PATENTSNumber Country 1 Date 12,512 British May 30, 1907

